1. Genome-wide association study of lifetime cannabis use based on a large meta-analytic sample of 32 330 subjects from the International Cannabis Consortium.
- Author
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Stringer S, Minică CC, Verweij KJ, Mbarek H, Bernard M, Derringer J, van Eijk KR, Isen JD, Loukola A, Maciejewski DF, Mihailov E, van der Most PJ, Sánchez-Mora C, Roos L, Sherva R, Walters R, Ware JJ, Abdellaoui A, Bigdeli TB, Branje SJ, Brown SA, Bruinenberg M, Casas M, Esko T, Garcia-Martinez I, Gordon SD, Harris JM, Hartman CA, Henders AK, Heath AC, Hickie IB, Hickman M, Hopfer CJ, Hottenga JJ, Huizink AC, Irons DE, Kahn RS, Korhonen T, Kranzler HR, Krauter K, van Lier PA, Lubke GH, Madden PA, Mägi R, McGue MK, Medland SE, Meeus WH, Miller MB, Montgomery GW, Nivard MG, Nolte IM, Oldehinkel AJ, Pausova Z, Qaiser B, Quaye L, Ramos-Quiroga JA, Richarte V, Rose RJ, Shin J, Stallings MC, Stiby AI, Wall TL, Wright MJ, Koot HM, Paus T, Hewitt JK, Ribasés M, Kaprio J, Boks MP, Snieder H, Spector T, Munafò MR, Metspalu A, Gelernter J, Boomsma DI, Iacono WG, Martin NG, Gillespie NA, Derks EM, and Vink JM
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, CD56 Antigen genetics, Carrier Proteins genetics, Cell Adhesion Molecules genetics, Female, Genome-Wide Association Study, Humans, Male, Membrane Proteins genetics, Middle Aged, Potassium Channels genetics, Potassium Channels, Sodium-Activated, Young Adult, Marijuana Abuse genetics, Marijuana Smoking genetics
- Abstract
Cannabis is the most widely produced and consumed illicit psychoactive substance worldwide. Occasional cannabis use can progress to frequent use, abuse and dependence with all known adverse physical, psychological and social consequences. Individual differences in cannabis initiation are heritable (40-48%). The International Cannabis Consortium was established with the aim to identify genetic risk variants of cannabis use. We conducted a meta-analysis of genome-wide association data of 13 cohorts (N=32 330) and four replication samples (N=5627). In addition, we performed a gene-based test of association, estimated single-nucleotide polymorphism (SNP)-based heritability and explored the genetic correlation between lifetime cannabis use and cigarette use using LD score regression. No individual SNPs reached genome-wide significance. Nonetheless, gene-based tests identified four genes significantly associated with lifetime cannabis use: NCAM1, CADM2, SCOC and KCNT2. Previous studies reported associations of NCAM1 with cigarette smoking and other substance use, and those of CADM2 with body mass index, processing speed and autism disorders, which are phenotypes previously reported to be associated with cannabis use. Furthermore, we showed that, combined across the genome, all common SNPs explained 13-20% (P<0.001) of the liability of lifetime cannabis use. Finally, there was a strong genetic correlation (rg=0.83; P=1.85 × 10(-8)) between lifetime cannabis use and lifetime cigarette smoking implying that the SNP effect sizes of the two traits are highly correlated. This is the largest meta-analysis of cannabis GWA studies to date, revealing important new insights into the genetic pathways of lifetime cannabis use. Future functional studies should explore the impact of the identified genes on the biological mechanisms of cannabis use.
- Published
- 2016
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